Similarities in physiological functions between humans and some non-human animals are well known. These similarities permit numerous pharmacological agents to provide therapeutic or diagnostic efficacy across species lines. Advantageously, the ability for a pharmacological agent to cross over species lines provides for therapeutic efficacy of new animal drugs in humans and new human drugs in animals.
However, the interspecies efficacy of a pharmacological agent can often be limited by certain fundamental differences which exist between humans and animals as well as between different animals. For example, interspecies differences at the cellular level for uptake, distribution, metabolism or elimination of a pharmacological agent can cause variability in the efficacy, toxicity or side effects of equivalent dosages administered to different animals or a human. In addition, differences in anatomy, size, disposition, availability of an accessible or safe administration route or reasoning capability often limits cross species utility. Moreover, housing conditions, frequency of administration or the skill level of the animal handler can limit practical utility of some agents across species lines. Thus, although physiological similarities exist between humans and non-human animals, these similarities are only one factor in the successful therapeutic effect of a pharmacological agent across species lines.
Safety, convenience, cost and skill level of the treatment provider are some of the factors affecting successful pharmacological treatment of conditions in animals. Often times animals are under the direct care of owners, trainers, or other handlers that lack expertise in administering a pharmacological agent to the animal. The general lack of second party payment systems for animal health care can make routine visits by a veterinarian (or other skilled animal care provider), or prolonged hospitalization, cost prohibitive to the owner. In addition, the fractious nature of some animals can preclude safe drug administration to the animal even by skilled handlers. Moreover, in rural areas, emergency situations frequently necessitate therapeutic action sooner than a veterinarian can arrive to provide the necessary treatment. Because of these and other factors unique to providing health care to animals, physiological similarity is only one factor affecting the therapeutic benefit of a pharmacological agent across species lines.
Typically, drugs are administered to animals orally or parenterally. And, while some pharmacological agents are available in an oral dosage form, to ensure that the necessary dose is administered, many agents must be administered by injection or directly to the stomach using a stomach tube. These administration methods can ensure proper dose administration, however, repeated administration via injection or stomach tube can quickly become irritating and stressful to the animal as well as dangerous to the animal owner or health care provider.
GB-A-981 372 describes a solid formulation suitable for oral administration to animals, being in the form of wafers readily adherent to the tongue or buccal mucosa and comprising a physiologically active substance, a solid non-toxic adhesive, a non-toxic humectant and a plasticizer.
EP-A-0 654 261 relates to a solid mucoadhesive therapeutic or hygienic composition, for human or veterinary use, intended to be administered by application to the buccal or nasal mucous membrane, this composition comprising, in mixture, a cellulosic ether gelifiable in the presence of an aqueous liquid, a homopolymer or copolymer of acrylic acid or a physiologically acceptable salt of that homopolymer or copolymer, and at least one therapeutic or hygienic active constituent.
WO-A-94/18925 describes a system for mucosally administering a macromolecular drug to the oral cavity comprising an inner drug/enhancer/polymer layer having one surface adapted to contact the mucosal tissue of the oral cavity and adhere thereto when wet and an opposing surface in contact with and adhering to an overlying inert layer, said inner layer containing from about 2 to 60 wt.-% of a bile salt enhancer, 5 to 65 wt.-% of a hydrophilic polymer and an effective amount of a macromolecular drug having a molecular weight of at least 500 daltons.
Hence, there is a need for effective diagnostic and therapeutic products and methods for animals that are humane, cost effective, easy to administer, and safe for both the animal and the health care provider.